Inserter systems, such as those applicable for use with the present invention, are typically used by organizations such as banks, insurance companies and utility companies for producing a large volume of specific mailings where the contents of each mail item are directed to a particular addressee. Also, other organizations, such as direct mailers, use inserts for producing a large volume of generic mailings where the contents of each mail item are substantially identical for each addressee. Examples of such inserter systems are the 8 series, 9 series, and APS™ inserter systems available from Pitney Bowes Inc. of Stamford Conn.
In many respects, the typical inserter system resembles a manufacturing assembly line. Sheets and other raw materials (other sheets, enclosures, and envelopes) enter the inserter system as inputs. Then, a variety of modules or workstations in the inserter system work cooperatively to process the sheets until a finished mail piece is produced. The exact configuration of each inserter system depends upon the needs of each particular customer or installation.
Typically, inserter systems prepare mail pieces by gathering collations of documents on a conveyor. The collations are then transported on the conveyor to an insertion station where they are automatically stuffed into envelopes. After being stuffed with the collations, the envelopes are removed from the insertion station for further processing. Such further processing may include automated closing and sealing the envelope flap, weighing the envelope, applying postage to the envelope, and finally sorting and stacking the envelopes.
The input stages of a typical inserter system are depicted in FIG. 1. At the input end of the inserter system, rolls or stacks of continuous printed documents, called a “web,” are fed into the inserter system by a web feeder 10. The continuous web must be separated into individual document pages. This separation is typically carried out by a web cutter 20 that cuts the continuous web into individual document pages. Depending on the mail run specifications, the cutter 20 can be set to cut sheets of different sizes. For example, some mailings may require letter size sheets, while others might include legal sized pages, or smaller than letter sized pages. Downstream of the web cutter 200, a right angle turn 300 may be used to reorient the documents, and/or to meet the inserter user's floor space requirements.
The cut pages must subsequently be accumulated into collations corresponding to the multi-page documents to be included in individual mail pieces. This gathering of related document pages occurs in the accumulator module 400 where individual pages are stacked on top of one another.
The control system for the inserter senses markings on the individual pages to determine what pages are to be collated together in the accumulator module 400. In a typical inserter application, mail pieces may include varying number of pages to be accumulated. When a document accumulation is complete, then the accumulation is discharged as a unit from the accumulator 400. An accumulator module 400 should also be adjustable so that it is capable of handling sheet accumulations of different sizes.
A conventional accumulator module 400 is described in U.S. Pat. No. 5,083,769 to Young, which is hereby incorporated by reference in its entirety. While this conventional accumulator has been found to operate successfully in transporting paper sheets at up to 150 inches per second (ips), it has been found to become unstable at higher speeds, such as 300 ips. Also, the conventional accumulator has been successful at accumulating sets of documents having on the order of eight sheets. However for improved processing capabilities it has become desirable to collate as many as twenty sheets.
Downstream of the accumulator 400, a folder 500 typically folds the accumulation of documents to fit in the desired envelopes. To allow the same inserter system to be used with different sized mailings, the folder 500 can typically be adjusted to make different sized folds on different sized paper. As a result, an inserter system must be capable of handling different lengths of accumulated and folded documents.
Downstream of the folder 500, a buffer transport 600 transports and stores accumulated and folded documents in series in preparation for transferring the documents to the synchronous inserter chassis 700. By lining up a backlog of documents in the buffer 600, the asynchronous nature of the upstream accumulator 400 will have less impact on the synchronous inserter chassis 700. On the inserter chassis 700 inserts are added to the folded accumulation prior to insertion into an envelope at a later module.